Procalcitonin or C-reactive protein, which is more instructive?

Procalcitonin, PCT is a hormone-free procalcitonin glycoprotein, a soluble protein released into the circulatory system of patients with severe systemic infections, especially bacterial infections. In normal physiological state, the PCT of CALC-1 gene transcriptional expression is limited to the thyroid C cells and the neuroendocrine cell kappa cells of the lung. The concentration of PCT in the healthy human body is very low [(0.033 + 0.003) ng/ml], and the level of PCT in the male body is higher than that of the female.

 

（1）PCT can be used in the diagnosis and differential diagnosis of sepsis.

（2）PCT can be used as a tumor marker.

（3）PCT level can be used to determine whether empiric antimicrobial therapy is effective.

（4）PCT levels to determine when antiseptic therapy is needed.

（5）reflect the severity of the patients with pancreatitis.

（6）Monitoring of complications of surgical operation and severe trauma caused by bacterial infection.

（7） PCT has been used to guide empirical antibiotics in the treatment of respiratory diseases with acute exacerbation of chronic bronchitis, community-acquired pneumonia and other bacterial infections.

 

Reference value of PCT        

The plasma concentration of PCT in healthy people is lower than that of 0.05ng/ml. Plasma PCT concentrations in the elderly, patients with chronic diseases, and less than 10% of healthy people were higher than 0.05ng/ml, with a maximum of 0.1ng/ml, but generally no more than 0.3ng/ml. The diagnostic value of PCT in patients with sepsis is more than 0.5ng/ml, and the concentration of PCT in patients with severe sepsis and septic shock fluctuates between 5-500ng/ml and 5-500ng/ml. A very small number of patients with severe infection had higher plasma PCT level than 1000ng/ml.

C-reactive protein, CRPA protein that agglutinates with C-polysaccharide, a polysaccharide component of nonspecific Streptococcus pneumoniae, and occurs in acute infections. When the body is under stress, inflammatory cytokines such as IL-6, IL-1 and TNF-ɑ can induce hepatocytes to synthesize CRP. In the normal serum, the content of CRP is very small, usually not more than 5mg/L, and is stable in the human body for a long time. Therefore, the change of the trace CRP can indicate the changes of the bodys physiological condition.

 

（1）identify bacterial infection and virus infection.

（2）The severity of inflammation that reacts to the body.

（3）detect connective tissue disease.

（4）Predictability of prognosis of malignant tumors.

（5）Predict the risk of cardiovascular disease.     

 

Reference value of CRP   

To detect CRP in serum by ELSIA，Normal adults and children were 0.068-8.2mg/L; if 10-99mg/L showed focal or superficial infection, the sensitivity of 100mg/L to septicemia or invasive infection was 100%.

 CRP criteria for risk assessment of cardiovascular disease: hs-CRP<1 mg/L is low risk, 1-3 mg/L is Moderate risk, 3 mg/L is high risk.

        

As an acute phase protein, the inflammatory response of the body can cause the increase of CRP. Therefore, it is difficult to distinguish whether the CRP is an infectious disease by this index. It is necessary to combine the clinical manifestation and other related auxiliary examinations to comprehensively consider the immune function and the defense mechanism in an comprehensive way.

As a new inflammatory index, the expression level of PCT is not affected by non infectious factors. Therefore, the diagnostic value of PCT is obviously better than that of leukocyte count and CRP. It is a highly sensitive and specific index. And it has been recognized as the most sensitive diagnostic index of sepsis. It has high value for the diagnosis of early infection, the identification of infection type and degree of infection, the application of antibiotics and so on. It is of great significance in clinical practice. 

Abebio developed ELISA Kits of CRP and PCT, with high sensitivity and stability, please contact us if you have any inquiry.

 

Cindy